Model, design and implementation of a low‐cost HIL for power converter and microgrid emulation using DSP

Abstract

In this study, the authors propose a method to implement a low-cost hardware-in-the-loop (HIL) system for power converters and microgrids design, test and analysis. This approach uses a digital signal processor (DSP) Texas Instruments as the HIL core. All the differential equations of the power converters are solved in real-time by the DSP and displayed in the digital-to-analogue outputs. Three different converters are modelled in this study: boost converter, single-phase inverter connected to the grid and three-phase inverter connected to the grid. Experimental results are obtained and compared to the HIL response. These results were made triggering the real converter and the HIL with the same open-loop pulse width modulation signal, showing high fidelity between the digital models over the real systems. In a second moment, a microgrid is modelled in the proposed HIL and tested with a closed-loop controller. The experiments show that the proposed hardware supports time steps as low as 1 μs or 1 MHz update rate, depending on the model. The proposed technique has the potential to reduce testing time and cost, once commercial HIL devices such as Typhoon, dSPACE and RTDS have a significant cost, not affordable or available to all the research community

Comparison of Different Design Alternatives for Hardware-in-the-Loop of Power Converters

“…However, it is nearly impossible to use microprocessors for high-frequency power converters in RT because of the small needed simulation step. For instance, a digital signal processor (DSP)-based HIL system for power converters such as Boost converter with a time step of 1 µs was proposed in [14]. Using the rule of 100 simulation steps per switching period, that would limit the switching period to a minimum of 100 µs and therefore switching frequencies under 10 kHz.…”

Design and Implementation of a Low-Cost Real-Time Control Platform for Power Electronics Applications

“…The same platform is used to test HIL of a boost converter and a full-bridge in power electronics applications [19]. Furthermore, a HIL implementation using a DSP LaunchPad C2000 Delfino F28377S is presented for microgrids applications in [20]. Three different converters are modelled in this study to validate the capabilities of the proposed DSP based HIL platform.…”

“…Besides, it is challenging to carry out a precise comparison of them, because most of the low-cost platforms are not commercially available and they are case a case implemented by research groups, tailored to a particular application. However, using the comparison reported in [20], it is concluded that the control systems implemented utilising some DSP platforms, can achieve time steps as low as 860 ns, higher than that achievable with the (relatively high cost) Typhoon system (≈560 ns) but still good enough to represent IGBTs in some typical application, for instance, microgrids, where the power converter switching frequency is about 10 kHz. As discussed in [8], the implementations based on FPGAs are also relatively low-cost alternatives for HIL and RTCP, achieving applications with low time steps.…”

Low‐cost hardware‐in‐the‐loop for real‐time simulation of electric machines and electric drive

“…However, in a recent paper [1], the authors have shown that it is possible to achieve for RT simulation of a power converter using the new generation of DSP processor. Slower than the FPGA approach, however easier to program, due to the high‐level language (C + +), with very low implementation cost, free software and friendlier environment for all engineering community.…”

“…Therefore, a digital model interfaced with real controllers and actuators running in RT can reduce cost and time for testing ideas. In addition, it provides the security of not working with real variables like high voltages, high current, high speeds etc [1].…”